Abstract

Studied in this paper is the inelastic seismic behaviour of asymmetric‐plan buildings using the histories of base shear and torque. The first step in understanding this behaviour is to construct the base shear and torque surface (BST) for the building, which represents all combinations of shear and torque that applied statically lead to collapse of the structure. Several factors controlling the shape of this surface, such as strength eccentricity and bidirectional ground motion, are identified. Also, their effects on the building responses are studied considering several structural configurations. The results obtained show that the BST surface, in conjunction with the base‐shear and torque histories, provides a useful conceptual framework for understanding the behaviour of asymmetric systems. Furthermore, using these surfaces, relevant aspects of the behaviour and design of such buildings become apparent even before dynamic analysis of the structure.